diff options
Diffstat (limited to 'libraries/base/GHC/Event/Thread.hs')
| -rw-r--r-- | libraries/base/GHC/Event/Thread.hs | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/libraries/base/GHC/Event/Thread.hs b/libraries/base/GHC/Event/Thread.hs index 367791354f..a330225622 100644 --- a/libraries/base/GHC/Event/Thread.hs +++ b/libraries/base/GHC/Event/Thread.hs @@ -30,7 +30,7 @@ import GHC.Conc.Sync (TVar, ThreadId, ThreadStatus(..), atomically, forkIO, labelThread, modifyMVar_, withMVar, newTVar, sharedCAF, getNumCapabilities, threadCapability, myThreadId, forkOn, threadStatus, writeTVar, newTVarIO, readTVar, retry,throwSTM,STM) -import GHC.IO (mask_, onException) +import GHC.IO (mask_, uninterruptibleMask_, onException) import GHC.IO.Exception (ioError) import GHC.IOArray (IOArray, newIOArray, readIOArray, writeIOArray, boundsIOArray) @@ -104,7 +104,10 @@ closeFdWith close fd = do mgrs <- flip mapM [low..high] $ \i -> do Just (_,!mgr) <- readIOArray eventManagerArray i return mgr - mask_ $ do + -- 'takeMVar', and 'M.closeFd_' might block, although for a very short time. + -- To make 'closeFdWith' safe in presence of asynchronous exceptions we have + -- to use uninterruptible mask. + uninterruptibleMask_ $ do tables <- flip mapM mgrs $ \mgr -> takeMVar $ M.callbackTableVar mgr fd cbApps <- zipWithM (\mgr table -> M.closeFd_ mgr table fd) mgrs tables close fd `finally` sequence_ (zipWith3 finish mgrs tables cbApps) |